A wide-angle viewing of the eye can take place in a simple manner through the use of a contact lens placed directly onto the eye. However, it is also possible to mount a separate optical device, which is spaced from the eye, on the microscope. If aspheric lenses are used for this purpose, which lenses guarantee alone a sufficient wide-angle viewing, then a side-reversed, upside-down image is created in the microscope just as this is the case with the contact lens, which image is acceptable for diagnostic purposes; however, during eye surgeries, which must be carried out advantageously at least at times also with a wide-angle viewing under stereo observation, a reversed stereopsis is created so that even experienced surgeons cannot be expected to handle such a control technique.
It is also already known to provide in such a microscope a device for the image reversion and image erection, as this is shown in the DE Patent No. 38 26 069 C2 (corresponding to U.S. Pat. No. 5,009,487). It is thereby particularly important that the additional structural parts do not significantly increase the height of the microscope because the surgeon must carry out the surgery and must look through the microscope at the same time, and the distance between the eyepiece of the microscope and the eye of the patient can therefore not be increased at random. Furthermore, the optical device for image reversion and image erection is, however, also supposed to be moved as quickly as possible into and out of the beam path of the microscope so that work can be done both in the front section of the eye and also in the fundus of the eye without having to change the microscope.